Techniques herein relate to semiconductor fabrication, and more particularly, to forming protection layers.
Field Effect Transistors (FETs) are widely used in the electronics industry with varied processing applications including switching, amplification, filtering, and so forth. Metal Oxide Field Effect Transistors (MOSFETs) are a common type of FET device used in microelectronics. Transistor structures typically include a metal or polysilicon gate contact energized to create an electric field within a semiconductor channel, which allows current to conduct between source and drain regions.
Semiconductor fabrication techniques commonly use high-k dielectric materials for the gate dielectric layer along with metals other than polysilicon for the gate electrode. Such devices may be referred to as high-k/metal gate transistors. Interfacial layers or passivation layers can form between these layers. Depending on materials used, an interfacial layer can be beneficial or detrimental. Sometimes the formation of a given interfacial layer is unintended, while other times it is designed.